Folding fin for motor boats



Mar. 5, 1929."

I H. L CHISHOLM. JR

rmmuu FIN you uororbons Filed June 28,; 1928 Patented Mar. 5, 1929.

-' UNITED STATES PA-TENT OF 1,703,868 FICE.

HARRY L. CHISHOLM, .m, or BUFFALO, New YORK,

ASSIGNOR r ALLOY BOAT CORPORATION, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

FOLDING FIN FOR MOTOR BOATS.

Application filed June 28,

'This invention relates generally to im-' provements in boats,but more particularly to a folding fin intended primarily for motor boats; I I Its chief object is to provide a simple and inexpensive fin of this. character which can be readily folded up out of theway for beaching the boat or for mooring it in shoal water.

Another object of the invention is'the provision of reliable and effective means for normally holding the fin in a rigid unfolded position. In the accompanying drawings 'Figure 1 is a side elevation of a motor boat equipped with my improvement. Figure 2 is a cross section thereof on line 2-2, Figure 1. Figure?) is an enlarged fragmentary longitudinal section taken in the plane of line 33, Figure 2. Figure 4 is an enlarged horizontal section on line 44, Figure 3. Figure 5 is a similarsection on line 55, Figure '3.

corresponding parts throughout the several views.

'By way of example, the invention has been shown in connection with a motor boat 10 operatedby an out-board motor'11 and-provided in its bottom with the customary step 12.

Unless skillfully handled, an out-board motor boat will capsize at high speed, especially when turning,and it is very essential that it be equipped with a fin or centering rib 13. My improved fin is so mounted that it can be readily folded laterally against the bottom of the boat for beaching purposes, and to this I end the same is disposed substantially centrally of the boat immediately in rear of the step 12 and is fixed at its upper end on a lon-.

gitudinal shaft 14 located above the normal water line of the boat and journaled at its front end on a suitable bearing 15 formed in the step and at its rear end in' a bearing bracket 16 fastened to the boat-bottom in the manner shown in Figure 3. The fin-shaft extends forwardly into the interior of the boat where it terminates in .a hand lever 17 preferably formed by bending the shaft upwardly at substantially right angles to its axis. By

turning the lever in one direction or the other transversely of the boat, the fin 13 is folded fiatwise against the underside thereof, as shown by dotted lines in Figure 2, in which position it lies in the space behind the step 12 and above the plane of thefront bottom portion of the boat.

. which is adapted, in the Similar characters of reference indicate 192a. Serial No. 289,015.

In addition to its folding action, the fin is capable of movement lengthwise of the boat a and for this purpose suflicient play is left between the front and rear edges of the fin and its bearings '15, 16 to permit its shaft to slide fore and aft in the latter, as indicated by full I and dotted lines, respectively, in Figure '3. (hen in its forward operative osition, the front edge of the fin 13 is adapte to. interlock with a rearwardly-opening locking notch 18 formed in a bracket 19 riveted or otherwise secured to the step 12 below the'axis of the shaft '14 and serving to rigidlyhold the fin in a vertical position and preventing torsional vibration thereof. In order to effectually hold the fin inits forward, unfolded position, a suitable latch 20 is provided which is hinged at 21 to a base plate 22 secured to the boat-bottom adjacent the step 12. This latohs-wings vertically and its front edge has'a notch 23 horizontal position of'sa'id latch shown by full lines in Figures 3 and 5, to engage the hand lever 17, thereby 4 holding the shaft against rearward displacement and the fin in looking engagement with the notch 18. Upon releasing the latch from the lever, by swinging it to the dotted line position shown in Figure 3, the fin is' free to be shifted rearwardly'to diseng ej tfrom its looking notch preparatory to' gilding it to .51.

position for beaching the boat or mooring it in shoal water. 'Any suitable means may be employed for retaining the fin in its folded position.

Applied to the shaft 14 and interposed be tween the front edge of the fin 13 and the ad- .jacent'bearing 15 is a flexible packing 24,

preferably in the form of a rubber sleeve, which, when the fin is in its unfolded position shown in Figure 3, is com ressed'in the manner shown, effectually sea ing the bearing 15, when the latch 20 is released from the hand lever 17, the packing expands and assists in shiftingthe shaft and its fin to the dotted line position shown in Figure 3.

I claim as my invention 1. In a boat, a foldable fin therefor fulcrumed at its upper end to the bottom of the boat, and means disposed in spaced relation to the fulcrum and engageable with one of the edges of the fin for rigidly holding it in its unfolded operative position.

2. In a boat, a foldable fin therefor fulcrumed at its upper end to the bottom of the boat, and a notched. bracket applied to the boat adjacent one of the upright edges of the fin and spaced from the fin-fulcrum, the fin being adapted to engage edgewise in the.

bracket notch in its unfolded position. I

3. 'In a boat, a fin hinged thereon for a combined movement both lengthwise andcross j wise of the boat, an edgewise finrece1v1ng member applied to the boatbeloW the hinge axis of the fin for holding it inits unfolded position, the latter being longitudinally movable "into and out ofengagement with said 1 member, and means for releasablyholding the fin in engagement with said holding member. i i

her for the fin journaled on the boat and movable a limited extent lengthwise thereof, and

means "disposed below and in substantially vertical alinenient with the axis of the hinge 'mem ber'for' retaining the fin in itsunfolded posit on, said fin be ng engageable'with and disengageable" from the retaining I means by shifting the' hinge member 11111 fore and aft direction; respectively.

i 5L In a boat, acom'bined oscillatory and longitudinally 'shiftable shaft journaled therein, a fin carried by said shaft and fold- I able; against the undersideof the boat a notchedbrace inemberwith which said fin is adapted to engagein its unfolded position, and a lever foractuating said shaft vto shift the same'lna, fore' and aft direction to bring said fin "into and out of engagement with its its folded and unfolded p0Sl C10I1S.; l

bracemember and'also to swing the fin to 6. Inja boat, a coinbined oscillatory and longitudinally 1 shiftable shaft journaled therein, a'fin carriedby said shaft and foldlable against the underside of the boat, a

' notched brace member with which said fin a boat, a fin mounted thereon for fold- 1 mg against the-bottom thereof, a hinge mem- H boat, an actuating' lever' forsaid fin a notched brace member disposed'below the fin-fulcrum, said fin being engageable edgewisewith the notch of said brace in its unfolded posit-ion,

and a latch disposed. above the fin-fulcrum and engageable with the actuating lever in the unfolded position of the fin.

8. In a boat, a foldable fin thereforful cruined at its .upper'end to the bottom of the boat, an actuating lever for-said fin, a brace member disposed below the fin-fulcrum and iseadapted to engage in its unfolded posi- 1t1on a'leverfor actuating said shaft to shift having a locking notch therein, said fin being shiftable on its fulcrum'fore land aft of the boat for bringing it into and out of engagement with said notch, and a latch disposed above the fin-fulcrum and havinga notch therein engageable with said hand lever in the unfolded position of the'fin;

v r 9. In a boat, a folda-ble fin therefor ful erumed atits upper end to the bottom of the boat and capable of a limited'fore and aft movement, an actuating lever for said 'fin, means engageable wlth the fin lnlts fore posi tion to hold it against movement about its fulcrum, and a pivoted latch engageable with said lever in the unfolded position of the fin to hold the latter in engagementwith said holding means. r a r HARRY" L. onrsnonnn. 

